1. Field of the Invention
The present invention relates to insulation cutting devices, and more particularly relates to an improved rotary type insulation cutter. Even more particularly, the present invention provides a rotary insulation cutting device having an improved cutter and router assembly which cooperate to form semi-circular insulation members for use with pipe. Even more particularly, the present invention provides an improved reciprocal rotary insulation cutting system having an improved feed system for conveying insulation blocks to be cut to the rotary cutter assembly.
2. General Background and Prior Art
In the industrial piping field, it is often required that individual runs of pipe be insulated to either preserve their heated or cooled condition, or to prevent injury to persons working near the pipes from burn and the like. The industry has developed a foam glass type insulation which is commercially available in usually block form and is known in the art, and is widely used commercially. The foam blocks are usually uniform in shape being generally rectangular and available from a number of commercial sources.
Since fluid conveying members are generally circular, such as conventional piping, a need exists for a cutting apparatus which can transform the rectangular block of foam glass members into semi-circular insulation members (see FIG. 8 in the drawings). The cutting of foam blocks into semi-circular or curved insulation members require a safe apparatus having means for feeding the blocks to the saw or cutting portion in a safe manner minimizing the chance for injury.
Many prior art type devices which do utilize a circular cutting member or cutting assembly do not have the cutting assembly firmly braced so that a true and precise cut is made.
Prior art type devices often do not provide a means for pushing the foam insulation blocks to and through the blade without the proximate placement of human hands. Devices without such material feed systems are hazardous for the worker who is employed to operate the device.
The block of insulation material to be cut normally experiences a high degree of stress when the cutting operation begins. Thus, there is a need for a suitable bracing assembly which can support the block of material on all sides yet allow for irregularities in blocks as they are fed to the saw or cutting assembly.
Since a number of blocks of insulation material would normally be cut in a given day on a given device, there is a need to provide a feed mechanism or a feed system which is fully automatic, thus being precise and accurate in cutting each successive block in the same shape.
A further need exists for a dual feed type feed system which supplies one block to be cut to the saw while the operator is busy removing and/or packaging the previously cut block of insulation material which now provides the desirable semi-circular insulation members adapted to fit for example heated or cooled pipe lines or piping systems.
Many prior art type devices are available which perform the cutting task in transforming rectangular blocks of foam glass material into generally semicircular insulation members which can be affixed to circular pipe structures. Some of these prior art type devices utilize a mandrel and elongated band saw type cutting arrangements. Such devices require skilled operators to properly mount the foam glass blocks on the mandrel and thereafter oversee the turning of the foam glass block on the mandrel and its cutting by a blade structure. Further, many types of mandrel and blade arrangements provide a plurality of blades to cut a plurality of semi-circular insulation members from a single foam glass block, see for example U.S. Pat. Nos. 4,059,035 and 4,140,036.
Rotary type saws are also known. Prior art type rotary saws are provided which generally attack the problem of cutting the foam glass block by providing a circular blade shaped to conform to the O.D. of the pipe to which the insulation member will thereafter be fitted. U.S. Pat. No. 3,060,779 issued to P. M. Taft and entitled "Cutting Apparatus" provides such a rotary type saw for cutting block type insulation material suitable for covering pipe, tanks, cylinders, tubes, and other circular type structure. The Taft device utilizes a plurality of circular blades, which are reciprocally driven from a linkage and belt member. Several blades are provided for cutting a number of insulation members from a single block of material.
In U.S. Pat. No. 2,841,193 issued to P. E. Petrofsky, there is provided a machine for sawing sponge like cellular glass. In that patent, a circular blade is reciprocally driven from a belt drive motor with a pair of circular blades performing the cutting. The device also teaches the cutting of elbow members, as shown in FIGS. 6-9.
In U.S. Pat. No. 2,751,941 issued to E. S. Smith, and entitled "Tubular Power Saw", a rotary saw blade is supported by roller bearings, which are motor driven. The saw is truly rotary rather than reciprocal as the above mentioned references.
In U.S. Pat. No. 2,983,175 issued to B. B. Harris, and entitled "Foam Glass Shaping Device", the device provides circular blades which are vibrated with the vibration being translated to the blade in order to cut the rigid but brittle foam glass material.
U.S. Pat. No. 3,312,131 provides another insulation forming device. The patent is issued to G. T. Gilmore and entitled "Insulation Forming Device", and provides a circular saw mounted on roller bearings which support the saw blade itself.
U.S. Pat. No. 2,780,896 issued to R. C. Jaye and entitled "Apparatus for Cutting Pipe Cover Sections from Cellular Material" provides a rotary cutting blade which is supported by rollers and belt driven with a motor. Recesses are provided in the cutting blade to accommodate the belt. The device suffers in that the blade must be thick enough to accommodate the thickness of the drive belt. Thus greater friction and excessive material cut thickness is required.
Prior art devices usually support the cutting assembly or blade itself at the periphery thereof usually by roller bearings or a pivoting arm. These and other prior art devices suffer in that they do not provide a true cut of the insulation foam glass material, especially of the inner recess portion of the smallest cut, which must fit closely to small diameter pipe.
These and other prior art devices suffer in that they do not provide a true cut of the insulation foam glass material, especially of the inner recess portion of the smallest cut, which must fit closely to small diameter pipe.
These prior art devices provide generally for a manual type feed which is hazardous to the operator in that the blades can often generate a tremendous amount of force applied directly to the block which must be held during the cutting operation.
Prior art type devices are generally a one direction feed, requiring a pause in the cutting operation while the operator removes the cut insulation members before he can reinsert an uncut block to be cut by the machine.
3. General Description of the Present Invention
The present invention provides an insulation material cutting assembly comprising a frame with a material feed surface being supported by the frame. The frame provides fore and aft material feed surface areas, with a circular cutting blade movably mounted on the feed surface and providing fore and aft cutting edges. The circular cutting saw can be placed generally between the fore and aft material feed surface. A router in the form of preferably one or two routing wheels is movably on the table for routing a semi-circular groove in a block of insulation material to be cut, preferably as the insulation block travels from the fore or aft material feed surface to the circular cutting blades.
A dual direction automatic feed associated with the feed table can feed a block of insulation material to be cut from the fore or from the aft material feed surface area along fore and aft feed lines respectively to the cutting blade. Each router wheel is mounted generally below the feed table with a semicircular portion projecting above adapted to rout a semi-circular groove in a block of insulation material which travels along at least a portion of the fore or the aft feed path.
In the preferred embodiment, a circular cutting saw provides a pair of circular blades which are mounted reciprocally on a supportive shaft at the feed table surface which shaft is rotatably supported by the feed table fore and aft of an opening in the table through which the circular blades project.
The router provides a routing surface which projects above the feed surface an area at least as great as the shaft upon which the circular cutting blades are mounted. In operation an insulation block to be cut will first be fed across one of the router wheels before engaging the circular cutting blades. The innermost recess will be cut in the block before it reaches the saw, with the recess passing through the cutting assembly at the shaft portion thereof. No binding of insulation material with the saw will be seen as with prior art devices, since the router pre-cuts a recess to accommodate the cutting assembly shaft before the block enters the cutting assembly.
Therefore, it is an object of the present invention to provide an improved circular cutting apparatus which allows cutting of an insulation block of material in two directions. Further, it is an object of the present invention to provide an automatic feed system which can feed insulation blocks to be cut to the rotary blade in one of two directions, allowing the operator to be unloading one piece of material while the other piece of material is being cut.
It is another object of the present invention to provide a more positive cutting assembly which utilizes a cutting router in cooperation with a shaft mounted circular rotary cutting blade, with the router first cutting a groove recess in the material block before the block engages the cutting assembly, with the recess passing the area occupied by the cutting assembly shaft.
It is another object of the present invention to provide an insulation material cutting apparatus which is simple and easy to manufacture and maintain.
It is another object of the present invention to provide an insulation material cutter having a bracing system which grasps the block of insulation material to be cut during the cutting operation when cutting stresses are applied directly to the block.
It is another object of the present invention to provide a guide system for guiding the insulation material block to be cut to the router and cutting assemblies, and therethrough.
It is another object of the present invention to provide a feed mechanism which feeds the block of insulation material to be cut to the router, to the cutting assembly, and therethrough, with continual feed until the insulation block of material clears the blade structure after cutting.
It is another object of the present invention to provide a dual direction material feed and associated switching system with an insulation cutting apparatus which shuts off the material feed when a single block of material has been fed through the cutting blade assembly and the desired cut made.